Ubuntu 18.04.3 cant find second monitor - Dell G3 - NVIDIA 1060 TI

I know there are several variations of this question out there, but I still haven't found a good fix or explanation.

I have a new Dell G3 laptop with an NVIDIA 1060 TI gpu. This system is set up for dual boot with windows/ubuntu. Ubuntu doesn't can't find the HDMI port and doesn't show my second monitor and I want to fix this.

I know the HDMI port works because the second monitor works in windows. The HDMI port on my other laptop (HP with AMD gpu) works fine, so I know its not Ubuntu and its not the cable. When I run xrandr on the Dell G3, it says HDMI disconnected when the cable is in.

I've tried unplugging the cable and rebooting. I've tried switching to lightdm. I've gotten all of the routine updates. None of these things fix the problem.

I'm pretty sure this a problem with the NVIDIA drivers. I've tried downloading the newest drivers from the NVIDIA website for this gpu in linux, but the problem persists. I've also purged the NVIDIA drivers and reinstalled them, and that also didn't work.

~$ lspci -k | grep -EA3 'VGA|3d|Display'

00:02.0 VGA compatible controller: Intel Corporation Device 3e9b
    Subsystem: Dell Device 0949
    Kernel driver in use: i915
    Kernel modules: i915
--
01:00.0 VGA compatible controller: NVIDIA Corporation Device 2191 (rev a1)
    Subsystem: Dell Device 0949
    Kernel modules: nvidiafb, nouveau
01:00.1 Audio device: NVIDIA Corporation Device 1aeb (rev a1)

Solution 1:

Nvidia driver is not installed. Downloading drivers from Nvidia site is a wrong method. Install the drivers this way:

Run in a terminal

sudo apt install nvidia-driver-435

Then reboot and disable Secure Boot in BIOS if you are using UEFI.